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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Thu Oct 14, 2010 1:57 am Post subject: Puzzle 10/10/14: C XY |
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I'm out of puzzles that solve with a single "wing".
Code: | +-----------------------+
| . . . | . 3 . | . . . |
| . 2 . | . . 7 | . . 9 |
| . . 4 | . . . | . . 2 |
|-------+-------+-------|
| . . . | 5 . . | 2 . . |
| 1 . . | . 6 2 | . 5 8 |
| . 4 . | . 7 8 | . . 6 |
|-------+-------+-------|
| . . . | 3 . . | 6 . . |
| . . . | . 1 . | . 2 4 |
| . 8 1 | . 2 4 | . 7 . |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Thu Oct 14, 2010 2:48 am Post subject: |
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How about an "almost wing" single step.........
Quote: | Axy-wing 3-57 vertex (37)r3c7 with pseudocell (35)r69c7 and fin ((5)r3c7; r1c7,r7c9<>5
[xy-wing=(5)r3c7]-(5=9)r3c5-(9=4)r4c5-(4=1)r4c8-(1=9)r7c8-(9=5)r9c7; |
Ted |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Thu Oct 14, 2010 3:54 am Post subject: |
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Or 2x XY-Chains using the same cells. No pseudo-cell and no fin cell.
Code: | (5=9)r3c5-(9=4)r4c5-(4=1)r4c8-(1=9)r7c8-(9=5)r9c7; r3c7<>5
+--------------------------------------------------------------------------------+
| 56789 1569 6789 | 2 3 169 | 457 468 57 |
| 3568 2 368 | 468 45 7 | 1 368 9 |
| 356789 13569 4 | 689 a59 169 | 37-5 368 2 |
|--------------------------+--------------------------+--------------------------|
| 6789 69 6789 | 5 b49 3 | 2 c14 17 |
| 1 39 379 | 49 6 2 | 47 5 8 |
| 2 4 5 | 1 7 8 | 39 39 6 |
|--------------------------+--------------------------+--------------------------|
| 4 7 2 | 3 8 59 | 6 d19 15 |
| 3569 3569 369 | 7 1 569 | 8 2 4 |
| 569 8 1 | 69 2 4 | e59 7 3 |
+--------------------------------------------------------------------------------+
# 79 eliminations remain
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Code: | (5=7)r1c9 - (7=3)r3c7 - (3=9)r6c7 - (9=5)r9c7; r1c7,r7c9<>5
+--------------------------------------------------------------------------------+
| 56789 1569 6789 | 2 3 169 | 47-5 468 a57 |
| 3568 2 368 | 468 45 7 | 1 368 9 |
| 356789 13569 4 | 689 59 169 | b37 368 2 |
|--------------------------+--------------------------+--------------------------|
| 6789 69 6789 | 5 49 3 | 2 14 17 |
| 1 39 379 | 49 6 2 | 47 5 8 |
| 2 4 5 | 1 7 8 | c39 39 6 |
|--------------------------+--------------------------+--------------------------|
| 4 7 2 | 3 8 59 | 6 19 1-5 |
| 3569 3569 369 | 7 1 569 | 8 2 4 |
| 569 8 1 | 69 2 4 | d59 7 3 |
+--------------------------------------------------------------------------------+
# 78 eliminations remain
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The giveaway: All bivalue cells except for the vertex ... and ... if the vertex is true for <5>, then it results in its own elimination along with the desired eliminations. |
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peterj
Joined: 26 Mar 2010 Posts: 974 Location: London, UK
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Posted: Thu Oct 14, 2010 12:18 pm Post subject: |
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I went Ted's path initially - but two steps as an xyz-wing to delete 7 from r3c7 and then the short xy-chain to delete 5.
Danny, I think your first xy-chain alone is enough to single-step if you incorporate (5)r2c1=r2c5 and so can eliminate (5)r9c1? |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Thu Oct 14, 2010 1:11 pm Post subject: |
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Very interesting since I initially had also spotted the xyz-wing (457) but it attracted me to the AXY-wing.
Both other observations are great insight into other perspectives of the same arrangement.
Ted |
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daj95376
Joined: 23 Aug 2008 Posts: 3854
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Posted: Thu Oct 14, 2010 4:25 pm Post subject: |
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peterj wrote: | Danny, I think your first xy-chain alone is enough to single-step if you incorporate (5)r2c1=r2c5 and so can eliminate (5)r9c1? |
Yes. But, I decided to just present the alternate perspective on Ted's solution since he put so much effort into it.
I find it interesting to see what can be found when a solution is reviewed. I'm always doing that to my solver's solutions and often find the alternate perspective to be just as interesting as the original. That's what I was trying to show here.
Of course, you need a solution before you can review it. Thanks Ted! _ _ |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Fri Oct 15, 2010 6:23 pm Post subject: |
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I played the XYZ-Wing (457), then an XY-Chain, r3c7<>5. |
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